Re: [PATCH] thinkpad-acpi: Enable microphone mute LED

Re: [PATCH] thinkpad-acpi: Enable microphone mute LED

[Andrew Lutomirski]

On Fri, May 27, 2011 at 12:48 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> On Fri, May 27, 2011 at 12:39:10PM -0400, Andrew Lutomirski wrote:
>
>> I don't have docs so I don't really know.  But the mute LED does not
>> appear to be controllable from the LED interface and when mute is lit
>> there's no sound regardless of what ALSA thinks.  When I light the
>> micmute light, I can still record sound just fine.
>>
>> The mic mute button does nothing on Windows unless the special driver
>> is installed, and that driver seems to mute the Windows mixer, so I
>> think there's nothing special other than a little userspace helper
>> going on.
>
> Hm. That makes things kind of tricky. While it's easy to just expose the
> LED, really we want to do it in such a way that userspace knows which
> LEDs it should be toggling while setting the microphone mute.

One thought: call the thing laptop::micmute and teach userspace to
look for an led with that name.

Do any of the ALSA or PulseAudio people have any preferences?

--Andy

Re: [PATCH] thinkpad-acpi: Enable microphone mute LED

[Matthew Garrett]

On Fri, May 27, 2011 at 02:22:26PM -0400, Andrew Lutomirski wrote:
> On Fri, May 27, 2011 at 12:48 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> > Hm. That makes things kind of tricky. While it's easy to just expose the
> > LED, really we want to do it in such a way that userspace knows which
> > LEDs it should be toggling while setting the microphone mute.
> 
> One thought: call the thing laptop::micmute and teach userspace to
> look for an led with that name.

Yes, I think standardised naming is going to be necessary to make this 
kind of thing work. That just leaves us with the additional problem of 
figuring out who has responsibility for toggling it and maanging 
permissions appropriately, but we'll get to that.

> Do any of the ALSA or PulseAudio people have any preferences?

Cc:ed Lennart to get his perspective.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

Re: [alsa-devel] [PATCH] thinkpad-acpi: Enable microphone mute LED

[Takashi Iwai]

At Fri, 27 May 2011 14:22:26 -0400,
Andrew Lutomirski wrote:
> 
> On Fri, May 27, 2011 at 12:48 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> > On Fri, May 27, 2011 at 12:39:10PM -0400, Andrew Lutomirski wrote:
> >
> >> I don't have docs so I don't really know.  But the mute LED does not
> >> appear to be controllable from the LED interface and when mute is lit
> >> there's no sound regardless of what ALSA thinks.  When I light the
> >> micmute light, I can still record sound just fine.
> >>
> >> The mic mute button does nothing on Windows unless the special driver
> >> is installed, and that driver seems to mute the Windows mixer, so I
> >> think there's nothing special other than a little userspace helper
> >> going on.
> >
> > Hm. That makes things kind of tricky. While it's easy to just expose the
> > LED, really we want to do it in such a way that userspace knows which
> > LEDs it should be toggling while setting the microphone mute.
> 
> One thought: call the thing laptop::micmute and teach userspace to
> look for an led with that name.
> 
> Do any of the ALSA or PulseAudio people have any preferences?

I don't know of any machines but Thinkpad providing such a LED
control, so I'm fine with any naming basically :)  Though, if there
are many of such mute LEDs, any parseable form like laptop::xxx-mute
would be better for future?


thanks,

Takashi